The present invention relates to devices used in agricultural equipment, and more particularly, to devices applied to controlling the magnitudes or rates of flow and losses of grain in the grain combine thresher.
The present invention can most efficiently be utilized in grain harvesters and grain cleaning machines.
Known in the prior art are devices for determining losses of grain in the grain combine thresher by determining the amount of grain sieved at the end of the rack, the amount of grain being proportional to grain losses through the rack.
One of these devices incorporates a funnel for collecting the separated grain at the end of the rack and an electroacoustic transducer or pick-up which is acted upon by grain from the funnel and connected to the means for registering the readings of the pick-up which is used as an indicator located in the sight view of the operator.
The grain seaved from the straw at the end of the rack is supplied through the funnel to the sensitive surface of the electroacoustic pick-up. The grains falling onto the sensitive surface generate electric pulses whose frequency is converted to the readings of the indicator calibrated in number of grains per unity of time.
In the mentioned device the errors for determining the losses of grain are influenced by the physical condition of grain, and particularly, the absolute weight of the grains which is changed depending on the conditions or duration of crop harvesting. This leads to errors in assessing and selecting the mode of operation of the grain combine.
Also known is a device which concurrently with the control of grain loss in the grain combine thresher measures and controls the amount of grain supplied to its hopper.
The mentioned device comprises a grain pick-up or transducer which measures the grain lost by the thresher and installed on the grain outlet from the additional separator of grain whose amount is proportional to total losses or transducer which measures the grain in the thresher, and a pick-up of the amount of grain supplied to the hopper of the combine and located in the upper head of the grain elevator feeding grain to the hopper. Each of the mentioned pick-ups in the device is independently connected with the independent means for registering the readings of the pick-ups which are used as indicators which, in turn, indicate the amount of grain lost by the thresher and the amount of grain supplied to the hopper of the grain combine. For transducer or pick-ups use can be made of electromechanical or capacitance pick-ups or volumetric pick-ups.
The pick-up for measuring the amount of grain proceeding to the hopper takes measurements of the total amount of grain supplied to the hopper at any given time.
The pick-up which measures the amount of grain lost by the rack of the thresher takes measurements of the amount of grain which is proportional to the total amount of grain lost by the rack at any given time.
The readings of the corresponding indicators are proportional to the quantity or rates of grain flow controlled by the pick-ups.
In the known device the pick-up which measures the amount of grain supplied to the hopper is located behind the transporting mechanisms of the grain combine which transfers the cleaned grain to its hopper. The flow of grain supplied to the hopper and measured by the pick-up is non-uniform due to the peculiarities of the auger or scrubber transporting mechanisms which supply grain in fluctuating quantities. The fluctuations in supply of grain results in considerable variations of the indicator readings and makes it difficult for the operator to use the readings of the instrument.
The location of the pick-ups which measure the amount of grain proceeding to the hopper directly in the hopper increases the lag period of the signal sent therefrom to the indicator as compared with the moment of supply of the plant mass to the grain combine. This results in a delay in changing the mode of operation of the grain combine which is changed by the operator in accordance with the signal obtained.
In the mentioned devices the errors of determining the losses of grain and the amount of grain supplied to the hopper are considerably influenced by the physical condition of grain, namely, its humidity and absolute weight which are varied due to the condition and duration of harvesting, thereby leading to establishing faulty modes for the combine operation.
The measurement of the total amount of grain supplied to the hopper calls for the utilization of large-size pick-ups of complex design which makes them expensive.